Systems are known to protect people and assets within secured areas. Such systems are typically based upon the use of one or more sensors that detect threats within the secured area.
Threats to people and assets may originate from any of a number of different sources. For example, an unauthorized intruder, such as a burglar, may present a threat to assets within a secured area due to theft. Intruders have also been known to injure or kill people living within the area.
Intruders may be detected via switches placed on the doors or windows of a home. Alternatively, the area may be monitored via a number of security cameras.
Security cameras may be used either actively or passively. In a passive mode, a guard may monitor images from each of the cameras through a monitor placed at a guard station. When the guard detects a threat, the guard may take the appropriate action (e.g., call the police, etc.).
Alternatively, the cameras may be used to actively detect threats. For example, a processor within the camera or elsewhere may monitor successive frames from the camera to detect changes that indicate the presence of an intruder. Upon detecting an intruder, the processor may alert a guard to the possibility of an intruder.
Many security systems operate automatically without the need for a human guard. In this type of system, a person arms the system when he leaves and disarms the system when he returns.
Once armed, a security panel monitors perimeter switches for activation and cameras for motion. While such systems work well, they do not always work well in darkened areas or where visibility is poor. Accordingly, a need exists for better methods of detecting intruders.